Posted on 5 February 2012 by dana1981, Alex C, Tom Curtis

On 19 July 2011, Monckton debated Richard Denniss, a prominent Australian economist, author and public policy commentator.  During that debate, Monckton delivered his usual Gish Gallop, repeating a number of long-debunked myths and misrepresenting climate science research.  A few days later, we at Skeptical Science detailed the various Monckton misrepresentations in the debate.

Monckton has recently responded to our comments, defending his debate arguments.  However, Monckton's defense amounts to little more than additional misrepresentations of the scientific literature and overall state of climate science (and economics).

Monckton also addressed John Cook throughout his response even though the Skeptical Science post was written by dana1981 (Dana Nuccitelli), as clearly indicated at the top of the post.  Unfortunately as we'll show here, Monckton's careless reading of the Skeptical Science post is symptomatic of his constant problems misreading - and consequently misrepresenting - the climate science literature.

Predicting Future Climate Change

Monckton originally claimed that the IPCC had said future climate change cannot be predicted.  We took issue with this claim, since the IPCC report specifically projects future climate change under various emissions scenarios.  In his response to us, Monckton provides an argument that is based on quote-mining the IPCC report and taking a single sentence out of context - the first sentence in the quote below.  The context of the quote is provided in the following sentences (emphasis added):

"The climate system is a coupled non-linear chaotic system, and therefore the long-term prediction of future climate states is not possible.  Rather the focus must be upon the prediction of the probability distribution of the system’s future possible states by the generation of ensembles of model solutions.  Addressing adequately the statistical nature of climate is computationally intensive and requires the application of newmethods of model diagnosis, but such statistical informationis essential."

In short, the IPCC is saying that we cannot precisely predict the future climate state; however we can produce a probability distribution of possible future climate states, which is precisely what the IPCC report proceeds to do.  Monckton has misrepresented the IPCC report by selecting a single sentence that serves a convenient purpose out of context, and choosing to ignore the text immediately following, not to mention essentially entire sections of the IPCC report where they do indeed detail the probabilities of future climate states from model ensembles.

Argumentum ad populum

In the debate, Monckton criticized Denniss' argument that given the overwhelming support amongst experts for the theory of anthropogenic climate change, we should take action to address it.  In our initial response, we noted that the climate science consensus is a consequence of the overwhelming evidence supporting human-caused global warming.  Monckton's recent response to us has been to dismiss this as being "a quibble," and instead elaborates on the reasoning behind his criticism of Denniss' arguments and the fallacy of argumentum ad populum.

While we have no objection to Monckton's statements on the fallacy in general, there is context to Denniss' argument that must be addressed.  As Denniss said at the beginning of his presentation, he is not a climate scientist, but an economist, and that his goal in this debate is

"to talk about the way that economists and certainly politicians as a general rule go about making decisions under uncertainty."

It is this theme that Denniss works with during his first ten minute presentation.  The underlying principle that he references for his argument is the "insurance principle," also known as the precautionary principle.  This is an economic argument, and can be summed up as the idea that in the presence of suspected but yet scientifically unverified harm from a course of action, the burden of proof for a lack of harm rests on the proponent of that action.  The implied result is that, in the abscence of proof of no harm, the action should not be taken, and/or actions to insure against the results of that action should be taken (subject of course to their own consideration under the precautionary principle).  Denniss likens this to buying insurance for your car, even though you don't have evidence that you will get into an accident.

There are two critical divergences from the argumentum ad populum Monckton asserts Denniss uses, and the precautionary principle which he actually does:

1) The argumentum ad populum fallacy in this case would argue that the consensus proves the human-caused warming theory is true.  Denniss does not make this argument.  Instead, he asserts that the consensus view of the science is reason enough for us to take action - there is an important distinction between asserting a claim is objectively true because of consensus on it, and asserting that it is economically convenient and advised to act as if it were true, because of the consensus on it.  Denniss advocated the latter, and as such did not commit the fallacy.

2) As Denniss explains when he first explicitly names the principle:

"Now, even though the scientific community leaves very little room for doubt, and very little room for uncertainty, even if there was uncertainty, most humans most of the time actually adopt the insurance [precautionary] principle when considering how to make decisions."

the precautionary principle assumes a lack of scientific consensus.  It is not required for consensus to be had, if we accept the precautionary principle, to act according to it.  This is not the case with argumentum ad populum, for which (at least a supposed) consensus of the proposed view is necessary to satisfy.

This is decidedly not the case with climate science, at any rate.  On the contrary, if we accept the precautionary principle, then we should be compelled by the scientific consensus on anthropogenic climate change, which is derived from the vast consensus of evidence, to take action to address it.

It is this economic argument that Denniss makes, and whether Monckton agrees with it or not does not justify his casting of it as the argumentum ad populum fallacy.

Climate Sensitivity

In the original debate, Monckton claimed that the Australian government's central climate sensitivity estimate is 5.1°C surface warming for doubled CO2.  In his recent response, Monckton again repeated this claim, attributing it to Australian economist Ross Garnaut.

"The estimate is that of Professor Ross Garnaut, the Australian Government’s economic adviser on climate questions. It is on that figure that his economic analysis – accepted by the Australian Government – centres."

It would be generous to call this a misrepresentation, because it is an outright falsehood.  Chapter 4 of The Garnaut Review actually states as follows (page 88-89, emphasis added).

"Projections of global mean surface air temperature for the 21st century show the increases continuing for all emissions cases. Figure 4.5 shows the projected temperature increases for the three emissions cases for the best-estimate climate sensitivity of 3ºC, with dashed lines indicating outcomes for climate sensitivities of 1.5ºC and 4.5ºC. Temperatures are projected to be slightly higher between 2020 and 2030 under the 450 case than under the 550 case, as rapid declines in aerosol emissions are associated with reductions in fossil fuel emissions, and the cooling influence decreases.

By the end of the century the global average temperature increase under the no-mitigation case is 5.1ºC, and still increasing at a high rate. The 550 and 450 cases reach 2.0ºC and 1.6ºC respectively, with the temperatures changing only minimally by 2100 in both cases."

In short, contrary to Monckton's misrepresentation, Garnaut and the Australian government use the IPCC climate sensitivity best estimate of 3°C for doubled CO2.  The 5.1°C warming figure refers to projectedwarming in to a business-as-usual scenario where CO2 more than doubles.

Monckton also claims there is no consensus regarding how much warming increased atospheric CO2 will cause - the climate sensitivity.  This is simply untrue.  Both the 2007 IPCC report and Knutti and Hegerl (2008) included literature reviews, examining climate sensitivity estimates using a wide range of methods, data, and timeframes.  In both cases the found a clear consensus that climate sensitivity is between 2 and 4.5°C for doubled CO2.

In disputing this consensus, Monckton lists a few papers which he purports demonstrate that climate sensitivity is low.  In some cases he has misrepresented the papers, as they make no assertions about climate sensitivity whatsoever.  In other cases, he references papers by the same few "skeptics" which subsequent research has demonstrated are flawed.

Douglass et al. (2004): attempted to estimate the climate sensitivity to changes in solar irradiance, and found a sensitivity parameter of 0.63°C per W/m2.  This equates to 2.3°C warming for a 3.7 W/m2 radiative forcing (the forcing caused by a doubling of atmospheric CO2).  This sensitivity is within the IPCC range, and thus this paper does not support a low sensitivity argument.

Douglass et al. (2007): deals with tropical troposhere temperatures and does not even discuss climate sensitivity.  In fact, the adiabatic lapse rate, which causes tropical troposphere warming, is a negative feedback.  Thus if it's missing, it actually undermines the low climate sensitivity argument.  Monckton also mischaracterizes the 'hot spot' as a fingerprint of human warming - it is not.

Coleman and Thorne (2005): same issue as Douglass (2007).

Shaviv (2005): has concluded that climate sensitivity is low because galactic cosmic rays have contributed substantially to global temperature changes.  Shaviv's conclusions are contradicted by virtually every other study on the subject of galactic cosmic rays.

Tsonis et al. (2006): fake skeptics frequently misrepresent this paper, claiming like Monckton that they attribute much of the recent warming to natural variability.  In reality the paper specifically discussed natural variability superimposed on an anthropogenic warming trend.  Moreover, a paper by co-author Swanson (2009) noted that if the climate is more sensitive to internal variability than currently thought, this would also mean climate is more sensitive to imposed forcings like CO2, and is thus an argument for high climate sensitivity.

Wentz et al. (2007): dealt with precipitation, not temperature changes or climate sensitivity.  The paper finds that while water vapor has increased as expected, precipitation has increased more than predicted by climate models.  This in no way supports low climate sensitivity, certainly not by threefold, as Monckton claims in his misrepresentation of this research [have emailed Wentz for comment]

Paltridge et al. (2009): is a paper about specific humidity which draws no conclusions about climate sensitivity.  Paltridge himself also noted that while their paper found decreasing specific humidity, it relied on problematic radiosonde (weather balloon data).  Subsequent research using satellite data has demonstrated that specific humidity is increasing as expected.

Douglass & Christy (2009): was published in Energy&Environment, which is not considered a legitimate peer-reviewed journal.  The paper attempted to estimate climate sensitivity based on just lower troposphere temperatures in the tropics, which could be described as 'cherrypicking'.  This is also the third Douglass paper referenced by Monckton.

Lindzen and Choi (2009): relied on short-term data with conveniently chosen starting and ending points, using data from only the tropics.  Several subsequent papers have demonstrated that this paper is flawed and its conclusions regarding low climate sensitivity are unsupported.

Spencer and Braswell (2010 and 2011): subsequent research has demonstrated that Spencer and Braswell were not testing climate sensitivity, but rather models' ability to reproduce the El Niño Southern Oscillation.  They also omitted inconvenient data from their published results.  Thus like Lindzen and Choi, their conclusions regarding low climate sensitivity are unsupported.

Loehle & Scafetta (2011): this paper used an extremely oversimplified climate model which fails to reproduce past climate changes, overestimated the natural contribution to 20th Century warming, and confused equilibrium with transient climate sensitivity, amongst its numerous fundamental flaws.

Overall, amongst the 12 papers which Monckton claims support low climate sensitivity, 5 do not even discuss climate sensitivity, 3 arguably suggest high climate sensitivity, 1 suggests climate sensitivity falls within the stated IPCC range, one tries to blame global warming on galactic cosmic rays, 1 was published in Energy&Environment, 4 have been debunked by subsequent research and/or are riddled with fundamental flaws.  Even ignoring the flaws and subsequent research, Monckton has only identified 6 papers which actually suggest climate sensitivity is low, as compared to the dozens of papers identified in Knutti and Hegerl (2008) which are consistent with the IPCC climate sensitivity range.

Not-So-Criminal Investigation

Monckton had claimed in his debate with Denniss:

"...the fabricators of the 2001 UN report - preported abolition of the Medieval Warm Period - are now under criminal investigation for defrauding taxpayers by tampering with data and results?"

Monckton continues to defend this slander against the many contributors to the 2001 IPCC report, and the many contributors to the section discussing millenial temperature reconstruction.  Only one of these scientists, Michael Mann, has been under any sort of investigation (as far as we know), and yet Monckton defames every single contributing scientist with a broad brush.  Monckton owes these scientists a retraction and an apology.

As for Michael Mann, Virginia Attourney General Ken Cuccinelli has indeed initiated a politically-motivated investigation against him, but it is not a criminal investigation.  According to the Virginia Fraud Against Taxpayers Act, the baseless accusations against Mann involve a civil, not a criminal offense.  Moreover, the investigation involves research funded by the State of Virginia, which does not include the Mann et. al 'hockey stick' research.  The one grant in question awarded to Mann in Virginia involves research which had very little to do with climate change (land-vegetation-atmospheric interaction in the African savannah). 

With these slanderous accusations, Monckton has grossly misrepresented reality on many different levels.

Medieval Warm Period

In both the original debate and recent post, Monckton suggested that the Medieval Warm Period (MWP) was warmer than Present.  To support this assertion, he first slandered the scientists contributing to the IPCC report, as discussed above.  More recently he referenced the website co2science.org, which has compiled regional records which suggest that local temperatures in certain geographic locations may have been hotter than Present.  Skeptical Science has previously discussed the misrepresentations of the scientific literature at co2science.

More importantly, as we noted in our original post, every peer-reviewed Northern Hemisphere and global millenial temperature reconstruction study has concluded that current temperatures are hotter than at the peak of the MWP.  This is even true for the temperature reconstruction by climate 'skeptic' Craigh Loehle.

Figure 3: Loehle 2008 temperature reconstruction (blue) with other temperature reconstructions (source: Wikipedia).

Even 'skeptic' temperature reconstructions demonstrate that Monckton is wrong and current temperatures are hotter than during the MWP.

Re-Writing History

In his debate with Denniss, Monckton claimed that Ben Santer singlehandedly added a statement to the 1995 IPCC report, attributing global warming to humans.  As we detailed in our response, this is simply an attempt to re-write history.  However, Monckton ignored our debunking of this myth, and simply repeated it once again.  We have now created a rebuttal to the myth "Ben Santer changed the 1995 IPCC report," and we recommend that Monckton actually read it this time, rather than continuing his attempts to re-write history.

CO2 Limits Will Help the Economy

In our original post, we pointed out the consensus amongst economists with expertise in climate that CO2 limits will help the economy, because climate mitigation is cheaper than adaption.  Monckton begs to differ, citing economics reviews by Tol (2009) and Lomborg (2007).  Tol (2009) concludes:

"A government that uses the same 3 percent discount rate for climate change as for other decisions should levy a carbon tax of $25 per metric ton of carbon (modal value) to $50/tC (mean value). A higher tax can be justified by an appeal to the high level of risk, especially of very negative outcomes, not captured in the standard estimates (Weitzman, forthcoming)."

"There is a strong case for near-term action on climate change, although prudence may dictate phasing in a higher cost of carbon over time"

Monckton has misrepresented Tol by claiming that his reserach concludes the costs of climate action will exceed the costs of inaction.  Tol's review also relies heavily on the work of Nordhaus, who has similarly been misrepresented by the fake skeptics, and who also has concluded that reducing CO2 emissions will save money.

Abrupt Warming

In discussing whether the Earth's climate is generally stable or unstable, Monckton made a number of incorrect claims about the Younger Dryas event.  For example, he referenced Antarctic temperatures, when the event is actually observable in Greenland, not Antarctic ice core records.  The temperature change also occurred over a span of approximately 40 years, not 3 years as Monckton asserts.

Regardless, Monckton's original argument that there just can't be a 5°C global surface temperature warming "overnight" (over approximately 250 years) simply has no basis in reality.  Given a sufficiently large radiative forcing, there is no physical reason why this warming could not occur.  Monckton also misrepresents the UK Met Office, claiming:

"We now have confirmation from the UK Met Office that there has been no “global warming” to speak of for 15 years."

The Met Office of course said no such thing. [What did they actually say?]

IPCC Graphic

Monckton takes issue with this figure from the 2007 IPCC report

The figure is used in FAQ 3.1 and the Technical Summary of Working Group 1.  Monckton asserts that this graph uses a "fraudulent statistical technique" and

"At each place where the altered graph is displayed, the incorrect conclusion is drawn that because trend-lines starting closer to the present have a steeper slope than those starting farther back, the rate of warming is accelerating and that we are to blame."

Again, this is a gross misrepresentation if not an outright falsehood.  The IPCC makes the following claims using this figure:

1)  The pace of warming accelerated over the course of the 20th Century. Notice the past tense.  Here is the specific claim (from the caption for Figure 1 of FAQ 3.1, emphasis added):

"Linear trend fits to the last 25 (yellow), 50 (orange), 100 (purple) and 150 years (red) are shown, and correspond to 1981 to 2005, 1956 to 2005, 1906 to 2005, and 1856 to 2005, respectively. Note that for shorter recent periods, the slope is greater, indicating accelerated warming."

2)  That the pace of warming over the last 25 years is greater than that in preceding years on the record.

3)  That the "... global average temperature has increased, especially since 1950."

All of these statements are true.  The IPCC does nto state that the rate of warming continues to accelerate, and does not use this figure to claim that humans are to blame for the accelerated warming, although in the FAQ 3.1 figure caption, the IPCC does explain how we know humans are the cause of the acceleration:

"From about 1940 to 1970 the increasing industrialisation following World War II increased pollution in the Northern Hemisphere, contributing to cooling, and increases in carbon dioxide and other greenhouse gases dominate the observed warming after the mid-1970s."

Monckton's claims of a "fraudulent statistical technique" are without merit, and a misrepresentation of the IPCC report's actual content.

Earth Has Warmed as Expected

After attempting to defend his use of the Central England Temperature record as an accurate representation of global temperature (it is not), Monckton asserts that the global surface temperature has only warmed 0.9°C since 1750.  This is simply inaccurate - the planet was in the midst of the Little Ice Age in 1750, and has warmed closer to 1.2°C since that time.

Figure 5: Various northern hemisphere temperature reconstructions (Mann et al 2008).

Monckton then compounds his error, claiming that:

"the radiative forcings we have caused since 1750 are equivalent to those from a doubling of CO2 concentration, suggesting that the transient sensitivity to CO2 doubling is around 1 C°."

Monckton has actually made 3 errors here.  The first, as noted above, is the incorrect assumption of 0.9°C warming since 1750.  The second is the claim that the radiative forcing since 1750 is equivalent to the forcing from doubled CO2 (3.7 Watts per square meter [W/m2]).  The actual net radiative forcing over that period according to the IPCC is 1.72 W/m2.  According to Skeie et al. (2011), the anthropogenic forcing since 1850 is about 1.4 W/m2.  Using these two incorrect values has led Monckton to an incorrect transient climate response estimate.

The transient climate response (TCR) is defined as the immediate temperature response when atmospheric CO2 levels double.  Until CO2 doubles, we can't know the exact TCR, but we can roughly estimate it using the formula TCR = dT/dF, where dF and dT are the changes in radiative forcing and global surface temerature, respectively.  Thus for a 1.7 W/m2 radiative forcing and 1.2°C warming, TCR is 2.6°C at doubled CO2.  This is toward the high end of the IPCC TCR range, but as noted, this is a very rough estimate.  Nevertheless, Monckton's estimate of 1°C TCR is off by more than a factor of two.

Monckton later repeats this same mistake on more recent data:

"Warming from 1950 to date was 0.7 C°. Net forcings since 1950 were 1.8 Watts per square meter...the transient warming in response to a doubling of CO2 concentration over the present century would be 0.4(5.35 ln 2) = 1 C°"

In this case, Monckton has the surface temperature change correct (approximately 0.7°C since 1950), but he once again has the radiative forcing wrong.  According to Skeie et al. (2011), the anthropogenic forcing since 1950 is about 1.2 W/m2 (and the natural forcings over this period have been close to zero).  Using the same calculation as above to estimate TCR, we get 2.2°C for doubled CO2, and once again Monckton is off by more than a factor of two, and contrary to Monckton's faulty assertions, the amount of warming we have seen is actually consistent with IPCC expectations.

Human Influence on the Climate

Monckton claims that the amount of warming that climate scientists expect (~3°C from doubled atmospheric CO2) is based on an "assumption" that climate feedbacks will behave like an electronic circuit.  Where Monckton gets this idea is a mystery, but as shown above, the IPCC climate sensitivity estimates are based on a wide range of observational data and other lines of evidence.

Monckton also claims that

"A climate subject to the very strongly net-positive feedbacks imagined by the IPCC simply would not have remained as stable as it has."

This is the myth "positive feedback means runaway warming."  The concept is incorrect because feedbacks suffer from the law of diminishing returns such that the feedbacks become weaker with each cycle, and thus do not cause a runaway effect.

Figure : simulated temperature response when using various feedback parameters (f).  After 3 to 10 cycles (depending on the feedback parameter), there is no more significant temperature increase.

When you add CO2 to this model system, there is indeed positive feedback, so even more CO2 will end up in the atmosphere than you dumped in from the burning of fossil fuels.  However, this does not give rise to a runaway scenario; eventually, the impact of that dollop of CO2 (or other feedback) comes to an end.